Lockheed Martin Corp lmt is on the verge of a major breakthrough in making a warplane that can fly at six times the speed of sound, Chief Executive Officer Marillyn Hewson said on Tuesday.

Speaking to reporters at the Lockheed‘s annual media day, Hewson said the company had already made progress on hypersonic programs and was producing an “aerodynamic configuration” which could reach Mach 6, or six times the speed of sound–enabling it to respond to security threats much more quickly than current fighter jets.

The U.S. Defense Department has said it wants to build what it calls a “prompt global strike” capability that would enable it to hit targets worldwide within an hour with conventional or nuclear warheads.

According to a report published by the Mitchell Institute for Aerospace Studies earlier this year, hypersonics had the potential to revolutionize the military much like stealth fighters did a generation ago.

“By fundamentally redefining the technical means of power projection, the U.S. can circumvent challenges facing the present force,” the report said.

Hewson said that Lockheed could develop and build a hypersonic demonstrator aircraft the size of a F-22 stealth fighter for less than $1 billion.

Orlando Carvalho, who heads Lockheed‘s Aeronautics division, said the government’s current plan was to produce a hypersonic weapon and field that before moving to develop and field a hypersonic aircraft.

In 2013, Lockheed unveiled plans for a hypersonic spy plane called the SR-72 that could fly at Mach 6, twice as fast as its famed SR-71 Blackbird, and said a missile demonstrating the new technology could fly as early as 2018.

Carvalho said the United States could realistically create a hypersonic weapon in the 2020s, but it would likely take until the 2030s to produce a hypersonic aircraft like the SR-72.

Separately, CEO Hewson said she has “no regrets” about buying helicopter maker Sikorsky for $9 billion in November, even though sliding oil prices have taken a bigger bite than expected from its commercial helicopter sales as energy companies have slashed spending.

Hewson said buying Sikorsky from United Technologies Corp utx was “absolutely a great opportunity” and Lockheed remained confident about its long-term prospects and said she expected oil prices to recover over the longer term.

Some analysts and industry executives have said Lockheed overpaid for the storied maker of the Black Hawk and Sea Stallion, underestimating the scale of the troubles faced by the oil and gas industry.

Lockheed Chief Financial Officer Bruce Tanner told Reuters in an interview that Sikorsky would generate more cash in future as it moves ahead on several U.S. military development programs, including a new presidential helicopter program.

“We did not buy this business for the next three years; we bought it for the next three decades,” Tanner said.